I have the evolution and am currently running the towing tune with 89 octane and timing +1. Has anyone ever ran the performance tune with lower octane and adjusted the timing down a little? Would it hurt anything as long as you hear no pinging? I just put my Terra Grapplers on and they take away a little of the low end grunt and I figured I could get it back with the performance tune.

 

Our PCM does a good job of controlling knock if you 'accidently' use a lower grade of fuel. If you are worried just set it back and *gear* it up.

 

Very correct... the knock sensor system on our motors is actually VERY advanced.

Not a huge deal but, try to stick with the octane recommended with your respective tune.

 

I'd stick with what they recommend. Edge recommends 91+ on the #3 tune. It's only .20cents more a gallon which will only be a few more dollars a fillup. Chaulk the few dollars more as the cost for better gas mileage and more of a fun -to-drive factor.

 

ASEMechanic has stated it is best not to do level 3 without at least 91 octane.

 

I've run premium grade gas ever since I've had a tuner. I'm an Evolution user now and have a question with a different twist. That is, same octane (91), same timing advance (3+), but running the level 2 tow vs. the level 3 performance. Question is, is there a whole helluva difference? I've read the level 2 tow tune runs a bit cooler (?) and may have some lower rpm grunt than the level 3. The level 3 is for higher rpm (over 3k). So if I want the advantage of the tow tune/lower rpm torque, I can simply increase my timing and have the best of both worlds? What's everyone say?

 

If you want to keep running 91 octane, and using level 2, it sounds good to me. That would be a good question to ask Bill on his radio show Thursday night, if we don't hear from him sooner.

 

I've been running 93 octane on level 3 with the timing set at +1.5.

Im getting 2 more mpg running 93 octane and its only a few more dollars, plus it makes the truck a whole new beast even with 35s.